Chromium 48 decays, after 6 have lives what’s fraction of the original nuclei would remain

Answer 1

The easiest way to do this problem is by using the simple formula F = 0.5ⁿ

This formula works for all 1st order decays. Here F = fraction remaining and n is the number of half lives that have elapsed (6).

F = 0.5⁶ = 0.015625 = fraction remaining.

Doing this the long way,

after 1 half life you have 0.5 left

after 2 half lives you have 0.25 left

after 3 half lives you have 0.125 left

after 4 half lives you have 0.0625 left

after 5 half lives you have 0.03125 left

after 6 half lives you have 0.015625 left